Does this mean that those metal spring "things" cannot be installed on the modified chassis?
They can be installed. Normally all three sides of that metal spring are sitting tight on the chassis. Now, due to the milling, the upper side of the metal spring is in the air and has no contact with the chassis because I needed to go down quite a bit so that the decoder fits nicely. I think a LokSound 5 micro is not that 'micro'.
I could try to shorten the sides of the metal spring.
I guess that springs installed in the chassis could replace the finger-type springs.
But for example I would not glue the bearing blocks to the chassis, or otherwise immobilize them. Those bearing blocks should be able to float slightly (while held under some spring pressure).
Correct, glueing the blocks to the frame is not an option.
Thomas